android模仿美团顶部的滑动菜单实例代码

以下是一个简单的实现顶部滑动菜单的示例代码：

1. 创建一个名为 `TopMenuActivity` 的 Activity，并在布局文件中添加一个 `ViewPager` 和一个 `TabLayout`：

<android.support.design.widget.TabLayout
    android:id="@+id/tab_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabMode="scrollable"
    app:tabGravity="fill"/>

<android.support.v4.view.ViewPager
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

2. 创建一个名为 `TopMenuFragmentPagerAdapter` 的 FragmentPagerAdapter，用于管理顶部菜单的 Fragment：

public class TopMenuFragmentPagerAdapter extends FragmentPagerAdapter {

    private List<Fragment> mFragments;
    private List<String> mTitles;

    public TopMenuFragmentPagerAdapter(FragmentManager fm, List<Fragment> fragments, List<String> titles) {
        super(fm);
        mFragments = fragments;
        mTitles = titles;
    }

    @Override
    public Fragment getItem(int position) {
        return mFragments.get(position);
    }

    @Override
    public int getCount() {
        return mFragments.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mTitles.get(position);
    }
}

3. 创建一个名为 `TopMenuFragment` 的 Fragment，实现顶部菜单的布局和功能：

public class TopMenuFragment extends Fragment {

    private RecyclerView mRecyclerView;
    private TopMenuAdapter mAdapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_top_menu, container, false);

        mRecyclerView = view.findViewById(R.id.recycler_view);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        mAdapter = new TopMenuAdapter();
        mRecyclerView.setAdapter(mAdapter);

        return view;
    }

    private class TopMenuAdapter extends RecyclerView.Adapter<TopMenuViewHolder> {

        private List<String> mData = Arrays.asList("美食", "电影", "酒店", "KTV", "景点", "更多");

        @Override
        public TopMenuViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_top_menu, parent, false);
            return new TopMenuViewHolder(view);
        }

        @Override
        public void onBindViewHolder(TopMenuViewHolder holder, int position) {
            holder.mTextView.setText(mData.get(position));
        }

        @Override
        public int getItemCount() {
            return mData.size();
        }
    }

    private class TopMenuViewHolder extends RecyclerView.ViewHolder {

        private TextView mTextView;

        public TopMenuViewHolder(View itemView) {
            super(itemView);

            mTextView = itemView.findViewById(R.id.text_view);
        }
    }
}

4. 在 `TopMenuActivity` 中初始化 `ViewPager` 和 `TabLayout`，并设置 `TopMenuFragmentPagerAdapter` 为 `ViewPager` 的适配器：

public class TopMenuActivity extends AppCompatActivity {

    private ViewPager mViewPager;
    private TabLayout mTabLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_top_menu);

        mViewPager = findViewById(R.id.view_pager);
        mTabLayout = findViewById(R.id.tab_layout);

        List<Fragment> fragments = new ArrayList<>();
        List<String> titles = new ArrayList<>();

        for (int i = 0; i < 5; i++) {
            fragments.add(new TopMenuFragment());
            titles.add("Tab " + (i + 1));
        }

        mViewPager.setAdapter(new TopMenuFragmentPagerAdapter(getSupportFragmentManager(), fragments, titles));
        mTabLayout.setupWithViewPager(mViewPager);
    }
}

这样就可以实现一个简单的顶部滑动菜单了。当用户滑动 `ViewPager` 时，`TabLayout` 中的选项卡会自动切换，而 `TopMenuFragment` 中的 RecyclerView 可以显示菜单项。你可以根据需要自定义菜单项的样式和功能。